Initial Checkbox selection on grid does not save the first time (Subsequent selections persist)

I am having an issue with a read only grid that is selectable. Upon page load users can select checkboxes, but those selections disappear. However, if the user selects the checkboxes a second time, the selections save and persist. It is only the first attempt at saving the selections that fails. 

Note: The first selection takes a long time to load and then disappears. The selections after that load normally. This issue does not exist in the interface designer (only on the live site)

selectable: true,
      selectionValue: local!selection,
      selectionSaveInto:{
        local!selection,
        
        a!save(local!selected, append(local!selected, fv!selectedRows)),
        
        a!save(local!selected, difference(local!selected, fv!deselectedRows))
      },
      selectionRequired: true,

Code above is where we save each selection in the read only grid.

a!startProcessLink(
  processModel: cons!PS_OPEN_NEW_TICKET_PM,
  processParameters: {
    periIDs: local!selection
  }
)

Code above is where we pass along the selections in the grid to a process model.